Light olefins and other related hydrocarbons serve as feeds for the production of numerous chemicals. Light olefins have traditionally been produced from petroleum sources. However, oxygenates such as alcohols, particularly methanol, ethanol, and higher alcohols or their derivatives, are used as alternative materials for light olefin production. These alcohols may be produced by fermentation or from synthesis gas. Oxygenates are particularly attractive because they can be produced from such widely available materials as coal, natural gas, recycled plastics, various carbon waste streams from industry and various products and by-products from the agricultural industry.
Although many oxygenates have been discussed in the prior art, the principal focus on producing the desired light olefins has been on methanol conversion technology, primarily because of the availability of commercially proven methanol synthesis technology. Various methanol to olefin (MTO) procedures for catalytically converting methanol into the desired light olefin products have been developed.
The product vapor stream from MTO process is generally a raw product stream containing impurities. For example, a product vapor stream from an MTO process typically contains light olefins, oxygenates, and water. The product vapor stream undergoes a process to remove the impurities and separate the light olefins.